AES Convention Papers Forum

Spherical Sound Source for Acoustic Measurements

A spherical sound source for acoustic measurements is proposed, consisting of a pair of coaxial loudspeakers and a pair of compression drivers radiating into a common radially expanding horn in full 360-degree horizontal plane. This horn‚Äôs vertical radiation pattern is defined by the enclosures of the LF arrangement. The LF membranes radiate spherically the 50 to 500 Hz band, whereas their HF components complete the horizontal horn reference ellipsoid-like diagram in both vertical directions to a spherical one. The assembly has axial symmetry, thus perfect horizontal polar pattern. The vertical pattern is well within ISO 3382 specifications, even without any ‚Äúgliding.‚Äù Comparative measurements against a purposely built typical dodecahedron revealed superior directivity, sound power capability, and distortion performance.